6638. Steel, S.. 1990. Your tiniest livestock.. Farm Journal (mid-January).Discusses the importance of the microbial population for a number of factors. Available P levels have increased in low input systems years after the last commercial P was added, probably due to microbial action. The microbial biomass from a LISA system had a higher proportion of N than that from a conventional system. Microbes improve soil structure. A marked increase in infiltration was observed after only one application of manure. John Doran found 10-26% more microbes on manured plots than unmanured. Also, there were more microbes in the top few inches of land planted to oats and clover than to corn or soybeans. This is mostly due to carbon levels and C:N ratios.

7085. Vandecaveye, S.C. and B.R. Villanueva. 1934. Microbial activities in soil: I. N fixation by Azotobacters and activity of various groups of microbes in Palouse silt loam.. Soil Science, 38(3):191-205.N fixation for 3 Palouse soils treated with lime & manure was determined. Quantities of N fixed varied with OM of soil. Unmanured soil with lime fixed 62 lb N per 2 million lb dry soil while manured soil with lime fixed 694 lb. during N fixation, the total N, N/C ratio, or the amount of nitrate present did not effect activity of azobacters. Transformation of organic residue was associated with a distinct sequence in developement of important groups of soil microbes through which the process of non-symbiotic aerobic N fixation is directly affected. T: N fixing powers of manured and unmanured Palouse silt loams. Microbial developement and CO2 production in manured Palouse silt loam. Microbial developement and CO2 production in virgin Palouse silt loam. Relation of N to fixed N and OM content of variously treated Palouse silt loams.